The present invention relates to further developments in preservatives for wood and other fibrous materials for protection against decay.
For more than a century, aqueous solutions of copper sulfate and zinc chloride have been used as wood preservatives. While these salt solutions have provided adequate protection against decay, they are, however, prone to certain disadvantages. Copper sulfate tends to attack iron and also, in certain instances, has only a weak preservative affect. Zinc chloride also acts as a corrosive and, in addition, has a lower preservative effect than the copper sulfate. For these and other reasons the aqueous preservative solution based on copper sulfate and zinc chloride have been replaced by other salt-based preservatives in which copper and zinc compounds are present.